At what concentration do Iron (II) and Iron (III) interfere with Silica method 8185?

Document ID

Document ID TE5943

Published Date

Published Date 13/03/2017
Question
At what concentration do Iron (II) and Iron (III) interfere with Silica method 8185?
Summary
Iron interference level in method 8185
Answer
 >5 mg/L of iron would start to interfere, but may be dependent on the water sample.  The operator can add disodium EDTA to remove the iron interference.

This information is also available in Standard Methods.